malariaparasiet

Malariaparasiet is the collective term for the protozoan parasites of the genus Plasmodium that cause malaria in humans and other primates. They require a mosquito vector for transmission and alternate between a vertebrate host and an Anopheles mosquito in a complex life cycle.

Within humans, several Plasmodium species produce disease, most notably Plasmodium falciparum, which can cause severe and potentially fatal malaria, and P. vivax and P. ovale, which can relapse from dormant liver stages known as hypnozoites. P. malariae and the zoonotic P. knowlesi also infect humans.

Transmission begins when an infected female Anopheles mosquito injects sporozoites into the skin. Sporozoites travel to the liver and invade hepatocytes, where they multiply before releasing merozoites that invade red blood cells. Asexual replication causes periodic fevers; some parasites develop into sexual stages (gametocytes) taken up by mosquitoes to continue the cycle.

Diagnosis relies on microscopic examination of stained blood smears and rapid diagnostic tests, with molecular methods used in reference settings. Treatment depends on species and drug resistance patterns, with artemisinin-based combination therapies commonly used for P. falciparum, and primaquine deployed to eradicate liver hypnozoites in vivax and ovale infections.

Prevention focuses on vector control (insecticide-treated nets, indoor residual spraying), chemoprophylaxis for travelers, and timely diagnosis and treatment to reduce transmission. Malariaparasiet infections remain most common in tropical regions, particularly in sub-Saharan Africa, Southeast Asia, and parts of South America, though global case numbers and mortality have declined in recent decades.